More particularly, the invention may apply in applications using the standard defined jointly by the ISO MPEG and the Video Coding group (VCEG) of the ITU-T called H.264 or MPEG-4 AVC (Advanced Video Coding) which is a video standard providing a more effective compression than the previous video standards (e.g. H.263, MPEG-2) while having a complexity of use that is reasonable and easily adaptable by the network applications.
Established in May 2003, the final version of the ITU-T reference document (JVT-G050r1) specifies only the aspects of the video coding of the most effective tool known to date. The main applications targeted by H.264 are:                real time duplex voice services (videophony) over cable or wireless (UMTS etc.) with a bit rate of less than 1 Mb/s,        current or high quality video services via satellite, xDSL, or DVD with bit rates of 1 to 8 Mb/s,        
low quality video with a lower bit rate such as the Internet (<2 Mb/s).
Extensions to the standard are currently being studied, in particular for high definition television (High profile) and for inserting scalability functions (SVC or Scalable Video Coding group).
The type of errors encountered during transmission and decoding may correspond to errors introduced by a transmission channel, like the family of wireless channels, from the conventional civil channels (e.g. transmissions on UMTS, WiFi, WiMax) to military channels (e.g. HF). These errors may be of the “packet loss” type (the loss of a sequence of bits or bytes), “bit error” (possible inversion of one or more bits or bytes, at random or in bursts), “deletions” (loss of known size and/or position of one, several or a sequence of bits or bytes) or else may result from a mixture of these various incidents.
The error sensitivity of variable-length codes is well known and its catastrophic behavior is infamous, in particular in a standard such as H.264/AVC, where the synchronization markers are present only at the beginning of the NALs. The transmission channels induce noise and fading in the transmitted streams, leading notably to errors.
A good way of preventing too much error propagation is to be able to detect them and, if possible, correct them and not simply mask them when they occur.
The methods used by the prior art to alleviate the problems resulting from the presence of errors are based mainly on:                the transmission of additional redundancy via a second channel or second stream, whether it be at the source (encoding by multiple descriptions, distributed encoding, use of “redundant slices”), on the network (repetition of the ARQ type, addition of FEC redundancy) or at the radio access (FEC),        the direct addition of redundancy in the initial stream, without taking account of the compatibility problem (rarer, more likely present in academic or theoretical works).        
It is therefore possible to add redundant slices obtained by multiple description encoding or “redundant slices”, which are based on a compression encoding with different reference points or compression coefficients, and not on the principle of error-correcting encoding.
Therefore, if there is an error, the use of the redundant slice will actually make it possible to decode (more or less effectively) the corrupted picture by decoding its duplicate. On the other hand, this will not make it possible to correct the errors that may have appeared, whether they be packet or bit errors.